Responsible organisation

Swedish Polar Research Secretariat

Abstract [en]

Tephra layers preserved within the Greenland ice-cores are crucial for the independent synchronisation of these high-resolution records to other palaeoclimatic archives. Here we present a new and detailed tephrochronological framework for the time period 25,000-45,000 a b2k that brings together results from 4 deep Greenland ice-cores. In total, 99 tephra deposits, the majority of which are preserved as cryptotephra, are described from the NGRIP, NEEM, GRIP and DYE-3 records. The major element signatures of single glass shards within these deposits indicate that 93 are basaltic in composition all originating from Iceland. Specifically, 43 originate from Grimsvotn, 20 are thought to be sourced from the Katla volcanic system and 17 show affinity to the Kverkfjoll system. Robust geochemical characterisations, independent ages derived from the GICCO5 ice-core chronology, and the stratigraphic positions of these deposits relative to the Dansgaard-Oeschger climate events represent a key framework that provides new information on the frequency and nature of volcanic events in the North Atlantic region between GS-3 and GI-12. Of particular importance are 19 tephra deposits that lie on the rapid climatic transitions that punctuate the last glacial period. This framework of well-constrained, time-synchronous tie-lines represents an important step towards the independent synchronisation of marine, terrestrial and ice-core records from the North Atlantic region, in order to assess the phasing of rapid climatic changes during the last glacial period. (C) 2014 Elsevier Ltd. All rights reserved.

Research subject

Identifiers

Funder

Swedish Polar Research Secretariat

Note

ISI Document Delivery No.: CK3KW Times Cited: 1 Cited Reference Count: 61 Bourne, A. J. Cook, E. Abbott, P. M. Seierstad, I. K. Steffensen, J. P. Svensson, A. Fischer, H. Schuepbach, S. Davies, S. M. Davies, Siwan/E-6915-2011; Svensson, Anders/A-2643-2010 Davies, Siwan/0000-0003-0999-7233; Svensson, Anders/0000-0002-4364-6085 European Research Council under the European Union [259253]; Denmark (SNF); Belgium (FNRSCFB); France (IFRTP); France (INSU/CNRS); Germany (AWI); Iceland (RannIs); Japan (MEXT); Sweden (SPRS); Switzerland (SNF); United States of America (NSF); Belgium (FNRS-CFB); Belgium (FWO); Canada (NRCan/GSC); China (CAS); Denmark (FI); France (IPEV); France (CNRS/INSU); France (CEA); France (ANR); Germany (Awl); Japan (NIPR); South Korea (KOPRI); The Netherlands (NWO/ALW); Sweden (VR); United Kingdom (NERC); USA (US NSF); USA (Office of Polar Programs); European Research Council [259253]; Climate Change Consortium of Wales [C3W]; STSM from EU-COST INTIMATE action [ES0907] This study forms part of the Tephra constraints on Rapid Climate Events (TRACE) project which aims to use tephra layers found in Greenland Ice Core and North Atlantic marine cores to consider the mechanisms of abrupt palaeoenvironmental change. The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement no [259253]. It is a contribution to the NorthGRIP ice-core project, which is directed and organised by the Centre for Ice and Climate at the Niels Bohr Institute, University of Copenhagen. It is being supported by funding agencies in Denmark (SNF), Belgium (FNRSCFB), France (IFRTP and INSU/CNRS), Germany (AWI), Iceland (RannIs), Japan (MEXT), Sweden (SPRS), Switzerland (SNF) and the United States of America (NSF). This work is also a contribution to the North Greenland Eemian Ice Drilling project which is directed and organized by the Centre for Ice and Climate at the Niels Bohr Institute and US NSF, Office of Polar Programs. It is supported by funding agencies and institutions in Belgium (FNRS-CFB and FWO), Canada (NRCan/GSC), China (CAS), Denmark (FI), France (IPEV, CNRS/INSU, CEA and ANR), Germany (Awl), Iceland (RannIs), Japan (NIPR), South Korea (KOPRI), The Netherlands (NWO/ALW), Sweden (VR), Switzerland (SNF), the United Kingdom (NERC) and the USA (US NSF, Office of Polar Programs). AJB, SMD and PMA are financially supported by the European Research Council (TRACE project: 259253) and acknowledge the support of the Climate Change Consortium of Wales (C3W). EC was financially supported by STSM funding from EU-COST INTIMATE action (ES0907). We would like to thank Dr Chris Hayward for his assistance with the use of the electron microprobe at the Tephrochronology Analytical Unit, University of Edinburgh. Thanks also to Gareth James, Gwydion Jones, Kathryn Lacey, Rhian Meara, Adam Griggs, and Lars Berg Larsen for help with the ice-core sampling. Kathryn Lacey is also thanked for her assistance with the slide preparation. This paper contributes to the EU-COST INTIMATE action (ES0907) and to the INTREPID project (Enhancing tephrochronology as a global research tool through improved fingerprinting and correlation techniques and uncertainty modelling an INQUA INTAV-Ied project (International Focus Group on Tephrochronology and Volcanism, project no. 0907). 1 Pergamon-elsevier science ltd Oxford Si